Musk has repeated his earlier stance despite a massive share price gains in the past couple of months. In May, he had tweeted that Tesla shares are highly-priced. The shares fell almost 10% on that day. The chief executive officer says he not concerned about the stock performance. Instead, Tesla is focusing on achieving sustainable volume and cash flow growth, which the majority of companies in the car manufacturing industry failed to do.   He said hundreds of new startups remained unsuccessful because they failed to impress buyers over the long term. Musk said only Ford (NYSE: F) and Tesla have not gone into bankruptcy in the entire industry. Tesla stock price soared more than 750% in the past twelve months. Tesla has generated profits in the past four consecutive quarters. Its operating cash flows came in around $520 million in the first half of this year.